Skinner M K, Fritz I B
J Biol Chem. 1985 Sep 25;260(21):11874-83.
The structural characteristics of proteoglycans produced by seminiferous peritubular cells and by Sertoli cells are defined. Peritubular cells secrete two proteoglycans designated PC I and PC II. PC I is a high molecular mass protein containing chondroitin glycosaminoglycan (GAG) chains (maximum 70 kDa). PC II has a protein core of 45 kDa and also contains chondroitin GAG chains (maximum 70 kDa). Preliminary results imply that PC II may be a degraded or processed form of PC I. A cellular proteoglycan associated with the peritubular cells is described which has properties similar to those of PC I. Sertoli cells secrete two different proteoglycans, designated SC I and SC II. SC I is a large protein containing both chondroitin (maximum 62 kDa) and heparin (maximum 15 kDa) GAG chains. Results obtained suggest that this novel proteoglycan contains both chondroitin and heparin GAG chains bound to the same core protein. SC II has a 50-kDa protein core and contains chondroitin (maximum 25 kDa) GAG chains. A proteoglycan obtained from extracts of Sertoli cells is described which contains heparin (maximum 48 kDa) GAG chains. In addition, Sertoli cells secrete a sulfoprotein, SC III, which is not a proteoglycan. SC III has properties similar to those of a major Sertoli cell-secreted protein previously defined as a dimeric acidic glycoprotein. The stimulation by follicle-stimulating hormone of the incorporation of [35S]SO2(-4) into moieties secreted by Sertoli cells is shown to represent an increased production or sulfation of SC III (i.e. dimeric acidic glycoprotein), and not an increased production or sulfation of proteoglycans. Results are discussed in relation to the possible functions of proteoglycans in the seminiferous tubule.
已明确了生精小管周围细胞和支持细胞产生的蛋白聚糖的结构特征。周围细胞分泌两种蛋白聚糖，分别命名为PC I和PC II。PC I是一种高分子量蛋白质，含有硫酸软骨素糖胺聚糖（GAG）链（最大70 kDa）。PC II有一个45 kDa的蛋白核心，也含有硫酸软骨素GAG链（最大70 kDa）。初步结果表明，PC II可能是PC I的降解或加工形式。描述了一种与周围细胞相关的细胞蛋白聚糖，其性质与PC I相似。支持细胞分泌两种不同的蛋白聚糖，命名为SC I和SC II。SC I是一种大蛋白，同时含有硫酸软骨素（最大62 kDa）和肝素（最大15 kDa）GAG链。所得结果表明，这种新型蛋白聚糖含有与同一核心蛋白结合的硫酸软骨素和肝素GAG链。SC II有一个50 kDa的蛋白核心，含有硫酸软骨素（最大25 kDa）GAG链。描述了一种从支持细胞提取物中获得的蛋白聚糖，其含有肝素（最大48 kDa）GAG链。此外，支持细胞分泌一种硫蛋白，SC III，它不是蛋白聚糖。SC III的性质与先前定义为二聚体酸性糖蛋白的主要支持细胞分泌蛋白相似。已表明，促卵泡激素刺激[35S]SO2(-4)掺入支持细胞分泌的部分物质中，代表SC III（即二聚体酸性糖蛋白）的产量增加或硫酸化增加，而不是蛋白聚糖的产量增加或硫酸化增加。结合蛋白聚糖在生精小管中的可能功能对结果进行了讨论。
